President Barack Obama is like a novice flier thrust into the cockpit of a 747. He’s pushing buttons, flipping switches and radioing air traffic control, but nothing’s happening. The plane is just slowly descending on its own, and while it may or may not crash, it at least doesn’t appear to be headed to any particularly useful destination.

Obama’s ineffectiveness, always a hallmark of his presidency, has reached a new cruising altitude this year. Not even a year into his second term, he looks like a lame duck and quacks like a lame duck. You guessed it — he’s a lame duck.

On the world stage, despite Obama’s exertions, Iran’s centrifuges are still spinning, the Israelis and Palestinians remain far apart, Bashar Assad is still in power, the Taliban are gaining strength and Iraq is gripped by renewed violence.

At home, none of Obama’s agenda has passed this year. Republicans aren’t bowing to him in the battle of the budget, and much of the GOP seems uninterested in House Speaker John Boehner’s vision of some new grand bargain with the president.

Obama has something worse on his hands than being hated. All presidents get hated. But Obama is being ignored. And that’s because he has no credibility.

A president enters office having earned a certain stock of political capital just for getting elected. He then spends it down, moving his agenda forward, until he collects a fresh supply by getting reelected.

But political capital is only the intangible substrate that gives a president his might. His presidency must also be nourished by credibility — a sense he can be trusted, relied upon and feared — to make things happen.

A president enters office with a measure of credibility. After all, he seemed at least trustworthy enough to get elected. But unlike political capital, credibility must be built in office. Otherwise, it is squandered.

Obama has used every credibility-busting method available to eviscerate any sense that he can be counted on. He’s dissimulated, proven his unreliability, ruled arbitrarily and turned the White House into a Chicago-style political boiler room. His credibility has been sapped with his political opponents, a public that thinks him incompetent, our allies, who don’t trust him, and, even worse, our enemies, who don’t fear him.

There’s not going to be any grand bargain on the budget this year. Republicans are not only miles from the president ideologically — they’re not going to trust him with holding up his end of the bargain. If they had a president they thought they could do business with, their spines might be weakening more quickly in the current budget impasse and they would be looking for an exit.

There are the unkept promises like closing Guantanamo, halving the deficit during his first term and bringing unemployment down below 8 percent as a result of the 2009 stimulus. Then there are the moments when one has to conclude that Obama could not have possibly been telling the truth.

His contention when selling Obamacare that people would be able to keep their insurance and their doctors is not simply “turning out” to be wrong. That some people would lose either their doctors or their insurance is an obvious result of a properly functioning Affordable Care Act. He could not possibly have known so little about his signature program that he didn’t foresee such a possibility.

Last year, the independent Politifact.com rated Obama’s vow to pass health care reform that reduces premiums for the average family by $2,500 a “promise broken,” suggesting that premiums might in fact go up slightly. Obama’s claim that Obamacare reduces the deficit is also probably wrong. In an article published Wednesday, Charles Blahous, the Republican-appointed Medicare Public Trustee, notes that he has estimated Obamacare would add $340 billion to federal deficits in its first decade, and that recent evidence suggests the tally is likely to be higher. But certainly Obama has performed a sleight of hand, since budget savings used to “pay for” Obamacare can no longer be used to subtract from the deficit.

Meanwhile, Republicans can’t trust the president to abide by any deal he might sign since he has a record of picking and choosing which laws to enforce. He stopped enforcing the Defense of Marriage Act before it was declared unconstitutional. Having not gotten the “Dream Act” out of Congress, he wrote it himself, choosing not to send certain children of illegal immigrants back to their native countries. He attacked Libya without the consent of Congress.

Sapping his credibility further is willingness to harbor and express vicious contempt for his ideological opposites, whom he variously describes as terrorists, “extremists,” and “enemies.” Behaving like a Chicago ward boss is not going to advance his agenda very far on Capitol Hill.

Obama’s failure to enforce his “red line” with Syria on the use of chemical weapons and punt the matter to a dubious weapons destruction process is only the latest example of his inconstancy. The president failed to maintain a needed troop presence in Iraq, resulting in disastrous and sustained violence that is wasting our efforts there; he tarried in supporting a potential Iranian uprising; he dumped a stalwart U.S. ally, Egypt, into the hands of the Muslim Brotherhood; he said Assad had to go, and then Assad didn’t go; he broke his promise to Hispanic voters to move immigration reform during his first term; and he dropped an additional $400 million in revenue on the table to blow up a potentially massive 2011 budget bargain with Republicans.

The only thing Obama can truly be counted on is to make his tee time on Saturdays, though the government shutdown has temporarily cramped his golf game.

During his first year in office, Ronald Reagan crushed an illegal strike by air traffic controllers by firing them all, defying charges that he was a union-busting thug and that planes would soon be dropping out of the sky. It was a moment that convinced observers at home and abroad that Reagan was not to be taken lightly, that he was a serious man of his word, and that he was to be respected and even feared. And so he got things done.

Obama has never shown similar fortitude to the world for the simple reason that he lacks it. Obama is not to be feared, or even trusted. And that’s a fatal flaw in a president.

Keith Koffler, who covered the White House as a reporter for CongressDaily and Roll Call, is editor of the website White House Dossier.